Carbonizing or like retort



July 14, 1931.

c. TURNER CARBONIZING OR LIKE RETORT Filed March 21, 1928 Ea z'ezz 5 0)" 25 ing the g 35 a spider extending across the retort.

making a substantially ,is not always necessary Patented July 14, 193i UNITED STATES PATENT OFFICE CHARLES TURNER, OF AIRDRIE, SCOTLAND GARBONIZING OR LIKE BETOBT Application filed March 21, 1928, Serial No. 2

A common device for discharging a vertical carbonizing or like retort which is being fed intermittently or continuously with coal or the like is an Archimedian screw revolvl; ing with its axis vertical in the lower part of the retort. Since the screw must be of such diameter that it substantially fills the cross section of the retort and the power required to turn it increases with its diameter, there is a limit to the cross sectional dimensions of a retort wherein the device is used, if consumption of power is of importance.

By my invention I use two or more Archimedian screws intermeshing with each other.

When more than two are used there is an additional advantage in retorts into the lower part of which steam or gas is to be introduced, particularly when the steam or gas is superheated to supply the heat necessary 90 for low temperature carbonization.

Various considerations lead to the desirability of introducing the steam by means of a pipe entering the retort in the region below the Archimedian screw and yet deliversteam above the screw and without using the shaft of the screw as a passage.

By using four or more screws the shafts of which are symmetrically arranged in relation to the axis of the retort, there is ob- 30 tained a space about the said axis in which the side thereof.

The use of the word axis is not intended to imply that the retort must necessarily be cylindrical.

Attention may be called to the fact that it to rotate the Archi- 63,349, and in Great Britain May 31, 1927.

median screws in order to pr charge. suffers a change of form the treatment so that its pose is changed. Hence natur oduce the dis- Q The material treated in the retort or structure during al angle of reby suitable selection of the pitch of the screws the conditions may be such that while the material rests on the screws during the treatment, 'cally slides down the screws when its remainlng stament is complete, the screws tlonary.

The accompanying it automatitreatdrawings illustrate the application of five Archimedian screws in the manner described above.

Fig. 1 represents a Vertical section through a retort embodying the invention,

Fig. 2 being a view in horizontal section on the line 22 of Fig. 1.

The retort is particularly a pplicable to a process of low temperature carbonization in which the fuel is heated by int roduction into the retort of superheated steam, the pressure being allowed to rise quickly released so that there of pressure in the retort and then are pulsations throughout the process. The retort or is surmounted by a hopper from which the material to be heated, generally coal, is discharged into mittent opening of valve d. this valve alternates with which admits coal In the lower end shafts also extend chamber 0 by inter- The opening of that of valve 6 into the retort.

of the retort is mounted a spider f through which extend the vertical shafts g of the Archimedian screws.

through glands h forming.

These part of the conical casting constituting the bottom of the retort. by gearin not shown,

The shafts are driven so as to rotate at the same speed in the same direction, indicated by arrows. This speed depends upon the Chill. actor of the material whlch 15 being heated in the retort and in some cases, may be reduced to zero.

Over a central opening in as already stated,

the spider is mounted a pipe 2' closed at its upper end and perforated as shown to permit issue of steam supplied through pipe 7a which forms a substanti ally steam-tight fit in the said opening. The oiftake Z of the retort contains a valve m which is opened at intervals (by the action a m-{part thereof; a hollowof any known device depending upon the attainment of the desired pressure in the retort) to permit rapid escape of elastic fluid from the retort, and closes again when the pressure in the retort has fallen to the desired limit.

In aaspec i fic. instance, '.a truncated c-onical cast ironretort is :used incarbonizingcann'el coal. It is ft. in diameter and of height 10 suitable for a charge of tons of the coal of size to pass a 4 mesh sieve. "Thediameter, length and pitch of each of the five screws are respectively 4 ft, 21 ins. and 14'ins. respectively.

The steam is superheated to 600 C. and is suppliednatthe rate ofv 150 lbstper minute.

iThe automaticallyoperated valve on inthe 'oiftakezat theitop of the retort opens 4 times 'perminute and remains-open 2 seconds-on 20: each: occasion.

rehangysrnce norm'ai'ly the cokesli'des down the screws at the desired rate.

iThe' foregoing 'is o'n'ly-a ,speclfic instance.

CHARLES TURNER; [-L. s.]

signed my In other'cases the screwsrequire to be rotated continuously at thespeed determined experiso 'mentally for the conditions attendinglthe process.

.The invention .is'also applicable to any process in which the temperature doesnot aprohi bit the use of the material of whichthe screws :are constructed.

'1 claim: i 1. *A'carbon'izingvertical retort comprising .-a shell. adapted for unimpeded :descent of 1a -oharge" iofsolid-material. through-the :npper ember of substan- -tially inverted cone shape constitutingthe .bOtiFOllT OffillGltOFtfEl plurality of vertical shafts extending through the said hollow "member into "the lower, part of the shel l,ian:d ,45 ianArch-hnedian screw fixed to the upper part of each of" the said shafts, said screws being aa dapted to together support and discharge a I charge of solidmaterial in. the shell and? each v-of them in'termeshing with and adapted to "rotate at-the same speed in thesaine direction was the edjacent screws.

"2. Acarbonizing vertical retort comprising wa shell adapted for; unimpeded descent of a charge-of solid material through the upper -part thereof, a conical hollow member :con-

1 stituting the bottom of the ret0rt,-at-least four vertical shafts extending through thesaid hollow member into the lower part'of the shell an'darrangedsymmetrically around the axis "woof: the-shell, an Archime-dian screw fiXG'Cls'tO 1 theupper pa'rt'ofeach of the said shafts, said --screws; =being ada'pted to together support and #discharge acharge of solid material in'the shell and'eaeh of them intermeshingwith and 65 -a;dapted*to rotate at the-samespeed in the 

